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Calculation of Electric Power: Instantaneous Power

The instantaneous current and voltage in an electrical circuit are given by:
i = Icos(50pi*t)
v = Vcos(50*pit + pi/6)

Determine an expression for the instantaneous power in the circuit p = iv, "AS THE SUM OF 2 COSINES"

If I is 0.003 Amps and V is 5 volts, calculate the maximum value of p, giving the answer in watts correct to 3 significant figures, and the first positive value of t at which it occurs.

Solution Summary

Electric Power is the product of Voltage and the Current. If V and I are expressed in terms of sin and cos, the product of the two expressions can be manipulated using standard trigonometric identities to get a consolidated answer. This problem illustrates this methodology with the help of a simple question.